PiP: Do nothing when tapping on resize drag handle.

When tapping on a resize handle (but not actually have any movement), we
should not do any resize operation.

This also fixes an issue that used to check againt the relative x,y
coordinate fot hit test. It should be using the raw-x,y pointers
instead.

Bug: 158300205
Test: Tap on the corner, nothing happens
Change-Id: Ib01428664125734cd6e253c29902b0f5b080a72f